/*
 * Copyright 2013 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.optaplanner.core.config.util;

import java.util.AbstractMap;
import java.util.LinkedHashMap;
import java.util.Map;

import com.thoughtworks.xstream.converters.Converter;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;

public class KeyAsElementMapConverter implements Converter {

    @Override
    public boolean canConvert(Class type) {
        return AbstractMap.class.isAssignableFrom(type);
    }

    @Override
    public void marshal(Object mapObject, HierarchicalStreamWriter writer, MarshallingContext context) {
       Map<String, String> map = (Map<String, String>) mapObject;
        for (Map.Entry<String, String> entry : map.entrySet()) {
            writer.startNode(entry.getKey());
            writer.setValue(entry.getValue());
            writer.endNode();
        }
    }

    @Override
    public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext context) {
        Map<String, String> map = new LinkedHashMap<>();
        while (reader.hasMoreChildren()) {
            reader.moveDown();
            map.put(reader.getNodeName(), reader.getValue());
            reader.moveUp();
        }
        return map;
    }

}
